GSTM1 polymorphism is related to risks of nasopharyngeal cancer and laryngeal cancer: a meta-analysis

BACKGROUND Accumulating data have reported that GSTM1 polymorphism may be related to nasopharyngeal cancer (NPC) and laryngeal cancer (LC). This meta-analysis was performed to investigate the relationship between GSTM1 polymorphism and risks of NPC and LC. METHODS Pubmed, Embase, and China National Knowledge Infrastructure (CNKI) databases were searched for potential articles. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the relationship of GSTM1 polymorphism with the risks of NPC and LC. I2>50% or P<0.05 indicates significant heterogeneity. When heterogeneity existed, the random-effects model was used to pool data, otherwise, the fixed-effects model was adopted. Publication bias was detected by Begg's funnel plot and Egger's regression. Quality of each study was evaluated by Newcastle-Ottawa Scale. RESULTS Thirty-two eligible articles were included. Pooled outcome suggested the significant relationship of GSTM1 null genotype with increased risk of LC (OR =1.28, 95% CI =1.05-1.54). Compared with hospital-based (HB) population, GSTM1 null genotype was also related to increased risk of LC (OR =1.38, 95% CI =1.06-1.80). Positive relationship of GSTM1 null genotype with enhanced risk of NPC was observed (OR =1.43, 95% CI =1.26-1.63). A similar trend was also observed in the subgroup analysis by source of control (population-based [PB]: OR =1.39, 95% CI =1.18-1.63; HB: OR =1.52, 95% CI =1.22-1.89). CONCLUSION GSTM1 null genotype is related to increased risk of NPC and LC.